Apparatus for the extrusion of billets

ABSTRACT

Billets are extruded from a container terminating in a die into which the extrusion ram or plunger is forced, to urge an extrusion or press disk toward the die orifice and drive the nonferrous metal of the billet therethrough. The ram is provided with a double-acting ejector disk which cleans the container wall and cooperates with the residual extrudable material, in the form of a lining or skirt, to withdraw it from the container.

w i Schl States Patent [191 iigelhoter May 14, 11974 1 APPARATUS FOR THE EXTRUSION 0F 3,034,642 5/1962 Graham 72/255 BILLETS 2,815,127 12/1957 Edgecombe 72/253 r 3,563,079 2/1971 Monie 72/273 [75] Inventor: Ferdinand Schlogelhofer, Amstetten,

t Aus Primary Examiner Charles W. Lanham Assigneei Vereinigte Metallwel'ke Assistant ExaminerRobert M. Rogers a sh Attorney, Agent, or f lgoss; Herbert Aktiengesellschaft, Vienna, Austria D b [22] Filed: June 15, 1972 211 Appl. No.: 263,104 57 ABSTRACT Billets are extruded from a container terminating in a [30] Apphcatmn Pnonty Data die into which the extrusion ram 0r plunger is forced,

June 16, 1971 Austria 5188/71 to urge an extrusion or press disk toward the die orir fice and drive the nonferrous metal of the billet there- [52] US. Cl. 72/255, 72/273 through. The ram is provided with a double-acting [51 Int. Cl. .1 B216 23/00 ejector disk which cleans the container wall and coop- [58] Field Of Search 72/255, 253, 273 erates with the residual extrudable material, in the .form of a lining or skirt, to withdraw it from the con- [56] References Cited tainer.

UNITED STATES PATENTS 9 C] 1 D F 3,073,442 1/1963 Muller 72/255 raw'ng 'gure 1 APPARATUS FOR THE EXTRUSION OF BILLETS FIELD OF THE INVENTION The present invention relates to the extrusion of billets and, more particularly, to an improved method of and apparatus for the extrusion of billets of nonferrous metal.

BACKGROUND OF. THE INVENTION toward an orifice at the end of the container, defined by a die. Between the ram and the material to be extruded (extrudable material) there is provided a press disk which is received with clearance in the cylinder defined by the container to permit the extrudable material to flow around the disk and form a lining or skirt. This lining prevents direct contact between the press disk and the wall and thereby serves as a lubricant for the pressing members. At the conclusion of the extrusion operation, the liningand any residue of the extrudable material within the container are removed in an ejection step, generally with the aid of a single-acting ejector disk serving to clean the wall of the cylinder. The cleaning operation takes place only during movement in onedirection and frequently is insufficient or ineffective for a satisfactory removal of traces of materials previously processed in the press, giving rise to the incorporation of such foreign materials in the extruded body, the formation of air pockets and the develop ment of piping defects in the extruded body.

OBJECTS OF THE INVENTION It is the principal object of the present invention to provide an improved billet press for the hot extrusion of metals whereby the aforementioned disadvantages can be obviated.

Another object of the invention is to provide an improved method of extruding metals, especially nonferrous metals, whereby contamination and damage to the extruded product can be avoided.

SUMMARY OF THE INVENTION These objects and others which will become apparent hereinafter are attained in accordance with the present invention, in a system for the hot extrusion of metal billets, particularly billets of a nonferrous metal, which comprises a billet container terminating at one end in a die provided with an extrusion orifice and receiving, at the other end, the usualpress ram or plunger, together with a lining-forming press disk ahead of the ram. According to the principles of thepresent invention, the leading or forward end of the ram is provided with a double-acting ejection disk which closely fits against the cylindrical wall of the cylinder bore receiving the billet and is effective upon movement of the plunger or ram in both directions to clean the wall and remove any residue therefrom.

The press disk, according to the invention, defines with the forward end of the'plunger or ram a compartment receiving the major part of the residue of the extrudable material when the assembly of ram and disk are thrusted fully intothe bore so that the space ahead of the ejection disk is completely filled with the extrudable material.

The ejector disk, according to the invention, has a doubly frustoconical configuration with flanks diverging outwardly from a central plane perpendicular to its axis toward the forward and rearward faces of these disks todefine cleaning edges having an acute-angle profile at these faces. Moreover, the disk is preferably slit or split and may be biased outwardly, the slit lying at an angle to a generatrix of the ejector disk.

Advantageously, the press disk is beveled rearwardly and/or provided with a step which opens rearwardly to define the compartment receiving the lining or skirt of extrudable material.

DESCRIPTION OF THE DRAWING The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which the sole FIGURE is an axial cross-sectional view, partly in elevation, of an extrusion system according to the present invention.

SPECIFIC DESCRIPTION In the drawing, there is shown a press ram or plunger 1 which can be forced into the cylindrical bore 9 of a billet container 6 by means not otherwise illustrated, e.g., a hydraulic press system. In addition, this system may include means for imparting a reverse impulsive or shock'force to the ram for the ejector phase ofits oper- .ation.

The ram 1 carries an ejector disk 2 in the form of a ring, the ejector disk 2 being solid or, as illustrated, split at 2a, the gap or slit Za-running at a slightly acute angle to a generatrix of the disk 2. The rearward face 2b of the disk lying in a plane perpendicular to the axis 10, may define a cleaning edge 20 with an acute-angle flank 2d extending frustoconically outwardly from a median plane P of thedisk 2, also perpendicular to the axis 10. The acute angle defined between the face 212 and the flank 2d is represented at a and may range between 2 and 15, preferably between 5 and 10. Similarly, a frustoconical divergent flank 2e of the ejector disk 2 terminates at the forward face 2f of the ejector disk in a cleaning edge 2g. The flank 2e may include a similar angle a with the face 2f.

The disk 2 is mounted upon a cylindrical shank 3a of a bolt 3 which is threaded at 3b into the ram 1 and terminates in a large-diameter circular head 30 which defines a slight clearance 3d with the wall 9 of the billet container. The head 30 of the bore may be so designed as to provide a limited axial play 2h between the leading face la'of the ram and the face 2b of the ejector disk 2. It has also been found to be advantageous to bevel the head 3c as shown at 3d.

During the extrusion phase of operation of the apparatus, the forward face 32 of the head 30 abuts the trailing face 4a of a. press disk 4, the function of which is to define the lining or skirt 5 of the extrudable material along the wall 9 of the billet container. To this end the press disk 4 may include a large-diameter shoulder 4b defining a relatively small clearance 4c between itself and the cylinder wall 9 into which the material of the billet 8 is backextruded during the press operation. He hind the shoulder 40 is the body 4d of the press disk which maydefine a somewhat larger clearance 4e with the wall 9 to permit backflow of the extrudable material into a compartment 4f in which the press lining or skirt 5 is accommodated. The rearward or trailing portion of the press disk 4 may be beveled or tapered rearwardly at 4g to define with the ram and the cylinder wall a compartment accommodating substantially the total volume of the lining material.

At the forward end of the cylinder 9, there is provided an extrusion die 7 whose orifice 7a defines the cross-section and configuration of the extruded rod or tube 19 formed from the billet 8. It should be understood that, where the press disk carries a mandrel or core, the extruded product can be a tube as opposed to the solid-cross-section body in the drawing.

The heated billet is inserted into the container 6 and is driven to the left by the ram 1 and the interposed press disk 4. After complete extrusion, i.e., after the disk 4 bottoms against the die, any residue of the extrudable material can be separated from the extruded body 19 by a shear or blade or remains connected to the press lining 5. As has been shown in the drawing, the ejector disk 2 is carried forwardly with the ram during the extrusion stroke and performs an initial clamping of the cylinder wall. Following extrusion and separationof the extruded body, the residue and the extrudable-material lining are impulsively ejected with the press disk 4 from the cylinder and, during the rearward stroke (to the right in thedrawing), any contaminants on the wall of the cylinder are removed. As a consequence the billet container is cleared for the next extrusion operation and the defects previously mentioned do not develop. In practical tests, it has been shown that the system completely avoids the problem of piping, contamination and air-bubble inclination characterizing earlier systems.

l claim:

1. A method of operating a billet-extrusion press, comprising the steps of:

inserting the billet in a billet container terminating in an extrusion die;

driving the extrudable material of said billet through said die by forcing a ram into said billet container;

said ram and in scraping contact with the inner wall of said container. 2. A system for the extrusion of billets, comprising:

a billet container terminating at one end in an extrusion die and adapted to receive a ram insertable through said container; and

a double-acting ejector disk fixed to said ram at a forward end thereof in the direction of extrusion of said material scraping the inner wall of said container and withdrawing the residue of extrudable material from said container and simultaneously cleaning same upon movement of said ram.

3. A system for the extrusion of billets comprising:

a billet container terminating at one end in an extrusion die and adapted to receive a ram insertable through said container; and

a double-acting ejector disk fixed to said ram at a forward end thereof in the direction of extrusion of said material scraping the inner wall of said container and'withdrawing the residue of extrudable material from said container and simultaneously cleaning same upon movement of said ram, said ejector disk being a ring and being split.

4. The system defined in claim 3 wherein said ejector disk is formed along its periphery with a pair of outwardly divergent frustoconical flanks terminating at faces of said disk perpendicular to the axis thereof.

5. The system defined in claim 4 further comprising a press disk ahead of said ram in the direction of extrusion ofsaid material and received within said container with all-around clearance.

6. The system defined in claim 5 wherein said press disk has a portion turned toward said ram and definingtherewith a compartment adapted to receive a lining of the extrudable material.

7. The system defined in claim 6 wherein said portion is rearwardly and inwardly bevelled.

8. The system defined in claim 7 wherein said ram includes a bolt having a shank, said ejector disk being mounted upon said shank.

9. The system defined in claim 8 wherein said bolt has a large diameter head lying along a face of said ejector disk, said shank being threaded into said ram,

said head abutting said press disk. 

1. A method of operating a billet-extrusion press, comprising the steps of: inserting the billet in a billet container terminating in an extrusion die; driving the extrudable material of said billet through said die by forcing a ram into said billet container; and ejecting a residue of extrudable material from said billet container and simultaneously cleaning the container wall in a single operation by advancing a cleaning disk directly behind said residue on said ram and in scraping contact with the inner wall of said container.
 2. A system for the extrusion of billets, comprising: a billet container terminating at one end in an extrusion die and adapted to receive a ram insertable through said container; and a double-acting ejector disk fixed to said ram at a forward end thereof in the direction of extrusion of said material scraping the inner wall of said container and withdrawing the residue of extrudable material from said container and simultaneously cleaning same upon movement of said ram.
 3. A system for the extrusion of billets comprising: a billet container terminating at one end in an extrusion die and adapted to receive a ram insertable through said container; and a double-acting ejector disk fixed to said ram at a forward end thereof in the direction of extrusion of said material scraping the inner wall of said container and withdrawing the residue of extrudable material from said container and simultaneously cleaning same upon movement of said ram, said ejector disk being a ring and being split.
 4. The system defined in claim 3 wherein said ejector disk is formed along its periphery with a pair of outwardly divergent frustoconical flanks terminating at faces of said disk perpendicular to the axis thereof.
 5. The system defined in claim 4 further comprising a press disk ahead of said ram in the direction of extrusion of said material and received within said container with all-around clearance.
 6. The system defined in claim 5 wherein said press disk has a portion turned toward said ram and defining therewith a compartment adapted to receive a lining of the extrudable material.
 7. The system defined in claim 6 wherein said portion is rearwardly and inwardly bevelled.
 8. The system defined in claim 7 wherein said ram includes a bolt having a shank, said ejector disk being mounted upon said shank.
 9. The system defined in claim 8 wherein said bolt has a large diameter head lying along a face of said ejector disk, said shank being threaded into sAid ram, said head abutting said press disk. 